Fluorescent flippers have been introduced as small-molecule probes to image membrane tension in living systems. This study describes the design, synthesis, spectroscopic and imaging properties of flippers that are elongated by one and two alkynes inserted between the push and the pull dithienothiophene domains. The resulting mechanophores combine characteristics of flippers, reporting on physical compression in the ground state, and molecular rotors, reporting on torsional motion in the excited state, to take their photophysics to new level of sophistication.
View Article and Find Full Text PDFLabeled ammonium cations with pK ∼7.4 accumulate in acidic organelles because they can be neutralized transiently to cross the membrane at cytosolic pH 7.2 but not at their internal pH<5.
View Article and Find Full Text PDFThis article describes four fluorescent membrane tension probes that have been designed, synthesized, evaluated, commercialized and applied to current biology challenges in the context of the NCCR Chemical Biology. Their names are Flipper-TR, ER Flipper-TR, Lyso Flipper-TR, and Mito Flipper-TR. They are available from Spirochrome.
View Article and Find Full Text PDFMechanosensitive flipper probes are attracting interest as fluorescent reporters of membrane order and tension in biological systems. We introduce PhotoFlippers, which contain a photocleavable linker and an ultralong tether between mechanophore and various targeting motifs. Upon irradiation, the original probe is released and labels the most ordered membrane that is accessible by intermembrane transfer.
View Article and Find Full Text PDFFluorescent flipper probes have been introduced recently to image membrane tension in live cells, and strategies to target these probes to specific membranes are emerging. In this context, early endosome (EE) targeting without the use of protein engineering is especially appealing because it translates into a fascinating transport problem. Weakly basic probes, commonly used to track the inside of acidic late endosomes and lysosomes, are poorly retained in EE because they are sufficiently neutralized in weakly acidic EE, thus able to diffuse out.
View Article and Find Full Text PDFSurface-confined synthesis is a promising approach to build complex molecular nanostructures including macrocycles. However, despite the recent advances in on-surface macrocyclization under ultrahigh vacuum, selective synthesis of monodisperse and multicomponent macrocycles remains a challenge. Here, we report on an on-surface formation of [6 + 6] Schiff-base macrocycles dynamic covalent chemistry.
View Article and Find Full Text PDFIn this review, the multifunctionality of dithieno[3,2-:2',3'-]thiophenes (DTTs) is covered comprehensively. This is of interest because all involved research is very recent and emphasizes timely topics such as mechanochemistry for bioimaging or chalcogen bonds for catalysis and solar cells and because the newly emerging privileged scaffold is embedded in an inspiring structural space. At the beginning, DTTs are introduced with regard to nomenclature, constitutional isomers, and optoelectronic properties.
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